#include <bits/stdc++.h>

using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
#define pb push_back
const int Nmax = 100000 + 5;
int n, m, cnt;
bool viz[Nmax];
vector<int> v[Nmax];

void dfs(int nod)
{
    viz[nod] = 1;
    for(auto i : v[nod])
        if(!viz[i])
            dfs(i);
}
int main()
{
    fin >> n >> m;
    for(int i = 1; i <= m; ++i)
    {
        int a, b; fin >> a >> b;
        v[a].pb(b);
        v[b].pb(a);
    }

    for(int i = 1; i <= n; ++i)
        if(!viz[i])
            dfs(i), ++ cnt;

    fout << cnt;
    return 0;
}